Xilin Iron and Steel Group’s Cuihongshan mine in the city of Heihe, near Heilongjiang’s border with Russia, flooded at around 3 a.m (1900 GMT), when 43 people were working underground, China Central Television (CCTV) said.

By 0340 GMT, 34 miners were rescued but nine remained trapped underground and the local government has dispatched 300 rescue workers to save the miners, CCTV and state news agency Xinhua reported.

The Cuihongshan mine, which started operations in February, has an annual mining capacity of 1.6 million tonnes, with magnetite output capacity of 850,000 tonnes, iron-zinc capacity of 700,000 tonnes and lead-zinc-copper capacity of 50,000 tonnes, according to the website of Xunke county, where the mine is located.

It has iron ore reserves of 70 million tonnes and non-ferrous metals reserves of 80 million tonnes.

The Heihe city government cited the mine for 26 safety violations in 2017 and briefly halted constructions to improve its safety condition, according to the city’s website.

A representative of the Cuihongshan mine told Reuters by phone that she is not aware of the accident. Other company officials could not be reached for comment.